Welding apparatus.



E. A. SHULER.

WELDING APPARATUS. APPLICATION man :uLY :a` 1916.'

1 ,238,206. Patented Aug. 28, 1917.

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STATES FATENT OFFICE.

EDWARD A. SH'ULER, OF CHICAGO, ILLINOIS, ASSIGNOR T0 THE PULLMAN COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 0F ILLINOIS.

WELDING APPARATUS.

To all whom it may concern:

Be it known that I, EDWARD A. SHULER, a citizen of theUnited States, residing at Chicago, inthe county ofCook and State of Illinois, have invented certain new and useful Improvements in Welding Apparatus, of which the following is a specification.

The invention has its special application, as herein set forth, to portable apparatus for vwelding nails orthe liketo the side sheets of steel cars for the securing in place of insulation, although obviously applicable in many other relations. u

A peculiarly advantageous distinctive feature of the invention is the utilization of the steel sheet itself as one terminal of secondary, whereby one lead is dispensed with, thus saving in weight of the welding tools, reducing the resistance and making it possible to use a lead twice as long as where two wires are employed as heretofore, adding to the flexibility of the lead and increasing the working capacity of the tool and ease in handling the saine, making it possible to use more tools with the same transformer due to reduced resistance and 'consequent economy of current. Other noteworthy features will readily appear to those skilled in the art.

In order that the invention and the manner of its employment may be readily understood a preferred embodiment oi the same is set forth in the accompanying drawings and in the following detailed description based thereon. Obviously the invention is capable of embodiment in other `structural forms than that chosen as an illustration, wherefore the drawing and description are not to be taken in an unduly limiting sense.

In the drawing- Figure 1 is a side elevation of the tool with a fragment of the plate in section;

Fig. 2 is a longitudinal section through the tool. taken on an enlarged scale;

Fig. 3 is a detail end view of the nail holding end of the tool;

Fig. 4 is a diagrammatic view showing the general wiring arrangement; and

Fig. 5 is a fragmentary sectional view showing the sheet with the nails welded thereon and illustrating the manner of use for the securing in place of insulation.

It has been found advantageous to use,

Specification of Letters Patent. Patented Aug 289 1917,7

Application led July 13, 1916.

Serial No. 109,054.

as indicated in Fig. 4, a step-down transformer with a potential drop across the secondary terminals of twelve volts, a switch, to connect the primary leads and the ground wire, and then clamp the terminal of the secondary lead to any suitable' part of the steel car for grounding the saine, the other secondary terminal being connected with the tool carrying the nails to be Welded and through which the circuit is completed.

The tool itself comprises a handle 11, suitably insulated from the secondary lead 12 and arranged to telescopically receive a casing 13 carrying a shank member 14, the latter having its end formed as a work holding head 15, provided with eccentrically arranged apertures 16 for the accommodation of nails 17. The casing 13 constitutes a shell surrounding a contact member 18 threaded or otherwise secured in the rear end of the shank 14 and the thread casing or shell bears at its rear end upon a coiled compression spring 19 confined within the casing 11 of the handle and having a rear abutment at 2O against -a shoulder formed within the handle. The forward movement of the work holder relative to the handle 11 is limited by a detent catch 11a, adapted for rotation to release the work holder for disassoeiating the parts. The forward end of the lead 12 has electrically connected therewith a conducting member 21 in the forward end of which is secured a second contact member 22, the contacts 1S and 22 being normally spaced from each other by means of the spring 19 and also being spaced from the shell 13.

rIhe wiring conditions being that previously indicated, the nail 17 is positioned within the head 15 -and brought to bear against the steel sheet 23. The handle 11 is grasped by the operator and pushed inwardly toward the sheet, compressing the spring 19 and advancing the contact member 22 against the contact member 18 whereby the circuit is completed through the nail head and the steel sheet of the car, welding the head of the nail to the sheet. The tool is then retracted, the first movement servingto move the contact member 22 to the rear and thereafter remove the tool as a Whole with the head from the nail.

As illustrating the utilization of the nails welded to the sheet steel plates of the car,

Fig. 5 shows'a sheet with a number of nails Welded thereto and a strip of insulating material placed over and transfiXed by the nails, the points of the nails being clenched over as indicated to hold the insulating felt in place.

I claim:

1. In a portable welding apparatus, the combination with a secondary, and a metallic body connected to one secondary lead, of metallic articles to be Welded to said body, a Work holder, a pair of contact elements one connected with the Work holder and the other With the other secondary lead, yielding means normally holding the contact elements in spaced relation, and means to bring the contact elements together to close the circuit to the article and body to be Welded.

2. In a portable apparatus for Welding nails to a metallic sheet, the combination with a secondary having one lead connected to the sheet, of a Work holder incluling a head for holding the nails, a contact e ement connected with the head, a second contact element connected With the other lead of the secondary, a spring normally holding the contact elements in separate relation, and means to force the said elements together to close the circuit through the nails and sheet.

3. In a portable apparatus for Welding nails to a metallic sheet, the combination with a secondary having one lead connected to the sheet, of a Work holder comprising telescopically arranged members, onemember including a nail holding head and a contact element connected therewith, the other member including a second contact element connected to the other lead of the secondary, a spring holding the two members normally in extended position with the Contact clements separated and yieldable under force to permit the said elements to be brought into contact to close the circuit through thc nails and sheet.

E. A. SHULER.

Witnesses:

O. E. BURGAR, F. E. KERR. 

